Variable maximum fuel limiting device



July 1, 1958 F. c. REGGlO VARIABLE MAXIMUM FUEL LIMITING DEVICE Original'Filed Feb. 3, 1939 5 Sheets-Sheet 1 4 m m 5 J 0/ m 1 9 J 0 r! 2 I o w 4 37 mm 9 8 4149M z 3 a .v w 6 IN 8 a I! l 1 5 m 8 8 W MM C 8 1 2 w o o 6 o M 3 8 a w I I O 3 a w 9 Md \\\\N\\ J S, w P 9 9 9 m 9 9 y 1953 F. c. REGGIIO 2,841,130

VARIABLE MAXIMUMFUEL LIMITING DEVICE Original Filed Feb. 3, 1939 5 Sheets-Sheet 2 12,. 3 750 rue-4 l/VJEZ'T/ON 60 74/ 5a 3mm y 19-58 F. c. REGGXO 2,841,130

VARIABLE MAXIMUM FUEL LIMITING DEVICE Original Filed Feb. 3, 1939 3 Sheets-Sheet 3 I30 I fi l L Bi I I05 =I L 78 I36 I n INVENTOR United States Patent VARIABLE MAXIMUM FUEL LIMITING DEVICE Ferdinando C. Reggio, Tampa, Fla.

Original application February 3, 1939, Serial No. 254,355. Divided and application July 29, 1947, Serial No. 764,322. Divided and application August 4, 1954, Serial No. 447,795. Again divided and this application March 25, 1957, Serial No. 648,096

48 Claims. (Cl. 123119) This invention relates to mechanisms for controlling the rate of liquid fuel flow of thermal powerplants, and

more particularly to devices for variably limiting the proportions between engine fuel ilow and engine air flow, or fuel-air ratio, in predetermined relation to certain changing operating conditions of the powerplant'. The present application is a division of my applications, Serial No. 447,795, filed August 4, 1954, Serial No. 764,322, filed July 29, 1947, and now abandoned, and Serial No. 254,355, filed February 3, 1939, and now abandoned.

An object of the invention is to provide improved devices of the type indicated.

Another object is to provide a liquid fuel control system for an engine including means for limiting the fuelair ratio and automatically changing the limit of said fuel-air ratio as a preselected function of various operating parameters.

Still another object is to provide an engine fuel control system having a variable stop for limiting the engine fuel-air ratio and means for changing the position of the stop in response to variations in certain operating conditions.

Further objects of the invention will be apparent from the following description, taken inconnection with the appended drawings, in which:

Figure 1 is a diagrammatic sectional view of a device embodying the invention;

Figure 2 is a fragmentary diagrammatic sectional view of another modified form of the invention;

Figures 3 and 4 are fragmentary diagrammatic sectional views of another modified form of the invention; and

Figure 5 is a diagrammatic view of the device of Figure 1 modified according to Figure .2. g

It will be understood by those skilled in the art that the invention is not limited to use in connection with the type of engine referred to herein, but may be practiced in connection with any suitable combustion engine, therrnal powerplant and the like.

Referring more specifically to the drawings, the arrangement disclosed in Figure 1 comprises an engine 60 having an induction passage 59 communicating with the inlet side of a supercharger or compressor 61 of any suitable type, which in turn leads to an induction pipe 62 and thence to the inlet port, not shown, of the engine. The passage 59 is controlled by a throttle valve 63 actuated through a lever 64.

A' casing 86 communicating through a large duct 81 with the induction pipe 62, contains air at induction pressure and temperature. An evacuated bellows 82 in said casing acts on lever 83 to operate rod 94 and pilot valve 84, 85 which controls admission of oil under pressure, usually led from the engine lubricating system through pipes 87 and 88 as indicated by the arrows, to opposite sides of piston 86. Low pressure oil is returned to the engine sump through line 89. A floating lever 90 is connected at its ends with rod 94 and piston 86, and at an intermediate point, with rod 91 which is connected,

2,841,130 I- atented July 1, 1958 through lever 92 and rod 93, with the horizontal arm of a bell-crank lever 74. To that end, the upper end of the rod 93 is provided with a pin upon which there is rotatably mounted a roller which is adapted to ride upon the upper side of lever 92. The position of the roller lengthwise with respect to lever 92 is determined by the adjustment of the bell-crank lever 98, whose lower arm is provided with a slot engaging the pin. Thus rotation of lever 93 varies the distance between the rod 93 and the fulcrum 92 of lever 92 and alters the ratio of the axial loads applied to the rods '91 and 93 under which the lever 92 is in equilibrium. Similarly, the lower end of the rod 93 is provided with another pin, which carries a roller riding upon the lower side of the horizontal arm of the bell-crank lever 74. This roller is positioned, lengthwise of lever 74, by means of a lever 79 (Figure 1) whose upper end has a slot engaging the pin. In the partial modification disclosed in connection with Figures 2 and 3, instead of the lever 79 there is provided a lever 137, which also serves variably to adjust the position of the lower roller lengthwise of lever 74. The lever 79 of Figure l, or the lever 137 of Figures 2 and 3, operates to control the effective arm ratio of lever 74. Constant contact between the rollers at the ends of rod 93 and the levers 92 and 74 is maintained as a result of the upward load transmitted by bellows 82 to the free end of lever 92, and counter-clockwise moment exerted on lever 74 by the tension spring 112.

Also enclosed within casing there is a bellows 95 which contains a certain weight of gas or other suitable fluid at constant volume. The high velocity of the air flow in the induction manifold 62 as well as the pulsations of pressure therein determine eddy currents and turbulence within the large and short conduit 81 and casing 80, thus causing an active thermic exchange, by conduction and convection, between the air flowing in the manifold 62 and the bellows 95. Moreover the thermal capacity of the latter usually is, or may be made, errtremely small. It follows that the fluid within bellows 95 is at all times maintained at the same temperature as the air in the pipe 62.

The absolute pressure within bellows 95 is therefore proportional to the absolute manifold or induction temperature. Bellows 95 and a similar and evacuated bellows 96 act against each other and on a lever 97 to operate the rod of a servo mechanism similar to the servo motor 86. Engine lubricating oil is led thereto and evacuated therefrom as indicated by the arrows. The pressure of the air in casing 80 acts in opposite direction-s on bellows 95. and 96, thereby balancing out the effect of any pressure change therein, so that the load transmitted to lever 97 by the two bellows is only dependent upon the induction or manifold temperature. The servo mechanism controlled by rod 100 acts on lever 98 to vary the angular adjustment of the lever and -in turn the operating distance of the rod 93 from the fulcrum 92' of lever 92. A spring 99 balances the load transmitted by the bellows to rod 100 and is so designed that the operating distance of the rod 93 from the fulcrum 92 of lever 92 is proportional to the actual absolute manifold temperature. Any temperature change in said induction manifold operates bellows 95 and in turn the servo mechanism to rotate lever 98 and vary the load of spring 99 until the balance of rod 100 in its neutral position is restored. Thus the load on rod 93 is proportional to the absolute pressure and inversely proportional to the absolute temperature in the induction pipe 62, and therefore is directly proportional to the air density therein.

A control lever 78 is adapted to modify the angular setting of lever 79 and in turn alter the distance of the lower end of rod 93 from the fulcrum of lever 74.

The engine 60 is provided with a fuel feed, such for 3 example as a conventional injection or metering pum 104 driven by the engine and comprising one or more pump elements connected by ducts or pipes 105 and nozzles 70 with the various engine cylinders. These nozzles 70 may be mounted in any suitable position, such as near the intake cylinder port or valve or inside the cylinder, as shown in Figure 3, or they may be mounted to inject fuel into the induction pipe 62 as shown in Figure 1.

The delivery of the engine fuel feed or metering pump 104 is dependent upon the adjustment of the control rod 106 which is actuated by a lever 127. This lever 127 is connected through a rod having a lost motion device such as an elongated slot 109 with the fuel control lever 108 which is operated by the pilot. The upper end of lever 127 is connected by means of a tension spring 112 to a rod 113 carrying valve elements 114 and 115 which control the admission of oil to opposite sides of the hydraulic servo motor piston 116. A tension spring 110 is provided which tends resiliently to maintain, against the action of spring 112, the pin 109 at the lower end of lever 127 applied against the left side of the slot 109 as shown in the drawing. Oil under pressure from the engine lubricating system is led to the servo motor 116 and is drained back to the engine sump as indicated by the arrows. In normal operation the rod 113 and valve elements 114, 115 are in neutral position and the load of the spring 112 is determined by the angular adjustment of lever 127. Clockwise rotation of the latter causes an increase of fuel delivery as well as an increase of the load transmitted by the spring 112 to the rod 113. This spring 112 is so designed that its load is proportional to the fuel delivery per cycle of the pump 104. A floating lever 117 is connected with piston 116, with lever 64 operating on the air throttle valve 63 and, through a lost motion device such as an elongated slot 121, with lever 127. A tension spring 118 tends to rotate the lever 117 clockwise, and stops 119, 120 limit its motion.

The bell-crank lever 74 has a horizontal and a vertical arm. The former is connected with the rod 93 and is therefore subject to a load which is proportional or substantially proportional to the engine induction air density or air charge per cycle, while the latter arm is connected with the rod 113 upon which the spring 112 exerts a load which is proportional to the engine fuel supply per cycle. As already stated, under steady operating conditions the rod 113 is in equilibrium in its neutral position. If the pilot rotates clockwise either the lever 108 to increase the fuel delivery (which increases the load of spring 112 proportionally), or lever 78 to decrease the fuel-air ratio (which decreases the distance between rod 93 and the fulcrum of lever 74 and therefore lowers the moment transmitted by bellows 82 through rod 93 to lever 74), or if the air charge per cycle decreases owing either to increasing altitude or increasing engine speed (in which latter case the regulating device 80 decreases the load transmitted to lever 74 by rod 93 proportionally), the rod 113 is displaced to the right to admit oil under pressure to the left side of the piston 116 and thereby rotate the lever 117 clockwise to open the air throttle valve 63 and increase the flow of air, which in turn increases the induction air density and the cylinder air charge, whereupon the regulator 80 causes the load transmitted by the rod 93 to the lever 74 to increase proportionally, thus moving the rod 113 back toward its neutral position. Displacement of piston 116 of the servo motor goes on until the balance of the rod 113 in its neutral position is again attained. This means that in the first case (where the pilot rotates the control lever 108 clockwise to increase the engine fuel supply), the combined actions of the servo motor devices 80 and 116 automatically open the throttle valve 63 to increase the engine air supply proportionally, thereby maintaining constant fuel-air ratio. In the second case (where the pilot rotates the mixture control lever 78 clockwise), the air charge is aeamso V s 4 automatically increased so as to bring the fuel-air ratio to the lower value corresponding to the new setting of the lever 78. In the third case (where the air charge per cycle decreases owing to increasing altitude, or increasing engine speed and corresponding reduction in engine volumetric efficiency), said device automatically increases the opening of the throttle valve 63 to maintain the fuelair ratio constant at the value corresponding to the set- I are proportional.

ting of the mixture control lever 78. The device will obviously operate in the opposite way when the pilot rotates the lever 108 or the lever 78 counter-clockwise, when the altitude decreases, or when the engine speed decreases.

The operation of the bellows device 80 upon changes of engine induction air pressure and temperature may more specifically be set forth as follows: the evacuated resilient bellows 82 exerts on the rods 94, 91 and 93 upward loads which are proportional to the induction pressure. In normal operation the rod 94 with the control valves 84 and is maintained in equilibrium in neutral position by a downward load of equal magnitude transmitted thereto from the calibrated spring 112 connected with the fuel metering pump 104. Thus for a given position of the temperature compensating lever 98 and a given setting of the manual control lever 78 the induction pressure and the load of spring 112 (and in turn the engine fuel supply) If now the aircraft climbs to higher altitude the induction pressure about bellows 82 decreases, and with it decreases the upward load transmitted by the bellows to the rod 94, while the downward load transmitted thereto from the spring 112 remains unchanged.

Thus the bellows 82 expands, the rod moves downward, and oil under pressure, admitted over piston 86,

displaces the latter downward, causing counter-clockwise rotation of lever 74 which sets in motion the servo motor 116 and causes rotation of lever 117 in a direction to open the throttle valve 63, thereby increasing the engine air supply. As a result of the increasing induction pressure, the bellows 82 contracts and reverses the motion of the rods 94 and 113. Meanwhile the servo motor 116 continues to open the throttle valve 63 until the induction pressure about the bellows 82 resumes the initial value, whereupon the rods 94 and 113 attain their neutral positions and the servo motors 86 and 116 are brought to a stop.

On the other hand, if the density of the induction air in duct 62 decreases because of increasing air temperature therein, then the temperature responsive bellows expands and sets in motion the depending servo motor which causes counter-clockwise rotation of lever 98 to increase the distance between the rod 93 and the fulcrum 92 of lever 92. Since the load exerted by bellows 82 upon rod 93 is inversely proportional to said distance, this decreases the load exerted by rod 93 on lever 74 and determined a movement of the rod 113 toward the right which sets the servo motor in motion in a direction to open the throttle valve 63 and so increase the induction air pressure as to compensate for the increased temperature thereof and maintain the induction air density and therefore the engine air charge per cycle constant. As the induction pressure increases, so increases the load transmitted by bellows 82 through rod 93 to lever 74, and the rod 113 moves back toward neutral position, until the proper higher value of induction pressure is attained; at which time the rod 113 resumes its neutral position and the servo motor 116 comes to a stop.

It is thus clear that with the above described mechanism the pilot directly controls the engine fuel supply by means of lever 108, while the air supply is automatically adjusted to keep the fuel-air ratio at the value corresponding to the setting of the mixture control lever 78 regardless of variations of operating conditions such as changes of temperature and surrounding air pressure. However, as the fuel supply is increased, or high altitude is attained, the lever 117 may come into contact with the stop 119, in which position the air throttle valve 63 is wide open, before the rod 113 is led back to its neutralposition, and the piston 116 will be further displaced to the right to rotate the levers 117 and 127 counter-clockwise and move the fuel control rod 106 to the left so as to decrease the fuel delivery until the fuel-air ratio assumes the value corresponding to the adjustment of lever 78 and the balance of rod 113 in its neutral position is attained. Inverse operation of the device will occur when either lever 108 or lever 78 are rotated counter-clockwise (to call for reduced fuel supply or richer mixture, respectively) or when the air charge per cycle tends to increase, as when diving to lower altitude.

From the foregoing it will be appreciated that where the engine air charge per cycle, or weight of air actually present in the engine cylinder during the compression and power strokes, is proportional to the induction density, then the mechanism shown in Figure 1 gives for each setting of the mixture control lever 78 a corresponding constant fuel-air ratio. However, in engines where the air charge is not inversely proportional to the induction temperature but varies as a difierent function thereof, an automatically constant value of fuel-air ratiomay bo obtained by establishing the suitable relation between rotation of lever 98 and distance of rod 93 from the fulcrum of lever 92 by means of a cam, substantially as shown in Figures 2 or 3.

. The arrangement described above in connection with Figure 1, in which the fuel-air ratio of the combustible mixture is adjusted manually by the pilot or operator through the mixture control lever 78 is not particularly suitable in connection with aircraft engines. According to the present invention, means responsive to one or more operative conditions, such for example as the induction manifold pressure, the manifold temperature, the engine speed, the engine temperature, are provided for controlling the engine air supply or the fuel-air mixture ratio automatically.

Operation of the engine 60 with best economy mixture is possible over a certain range of power, beyond which the engine cannot safely be operated without resorting to some additional enrichment of the mixture to suppress over-heating and detonation. A temperature responsive element 130, Figure 2, mounted at a suitable point of the engine such as a cylinder head or exhaust port, is connected with a bellows 131 placed to act against an evacuated bellows 132 so that changes in the pressure surrounding the bellows act in opposite directions on said two bellows and have no effect on their operation. Temperature changes about element 130 operate the bellows 131and in turn the rod 133 of a servo mechanism, similar to those already described in detail, to control the angular adjustment of lever 134 and cam 135 and to vary the force of spring 136 acting on rod 133. An increase in temperature of element 130 lowers the rod 133 and in turn rotates lever 134 clockwise thereby increasing the load of spring 136 until the balance of rod 133 in its neutral position is restored. Cam 135 is adapted to operate lever 137 which has the same function as lever 79 previously described, so that for each value of the temperature of element 130 it determines a corresponding predetermined minimum possible value of the fuel-air ratio. Mixture control lever 78 and lever 137 are connected through a lost motion device such as an elongated slot 138 and a tension spring 139 whereby the lever '78, whatever its adjustment may be, does not oppose counterclockwise rotation of lever 137 when the latter is rotated by cam 135. it will be clearly understood that in order to obtain the foregoing results the structure represented in Figure 2 may be combined with the mechanism of Figure l by eliminating from the latter the lever 79 and substituting therefor lever 137 and the structure indicated by numerals 130 to 135 in Figure 2. Such an arrangement is illustrated in Figure 5.

Moreover, according to the invention, in order to ootain a fuel-air mixture ratio which varies automatically as a predetermined function of other operative conditions, lever 79 of Figure 1 may be eliminated, and in substitution therefor there may be provided lever 137 actuated by a cam having two distinct ways of reversible adjustment, for example a slidable and rotatable cam 146 as shown in Figures 3 and 4, there being provided means responsive to engine operative conditions for adjusting said cam in said two distinct ways, whereby the mixture ratio may automatically be caused to vary as a predetermined function of two independent variables, said function being dependent upon the configuration of the cam.

lower end of rod 93, shown in Figure 1, for adjusting the effective length of lever 74, and has therefore the same function as the upper arm of lever 79. The lower arm of lever 137 has a lost motion connection with a rod 138 which may be actuated by way of the manual control member 78 of Figure l. A third, horizontally extending arm of lever 137 of Figures 3 and 4 is actuated by the cam 146 which may be axially and angularly adjusted by engine condition responsive devices, shown in Figures 4 and 3 as mechanisms responsive to the engine speed and to the manifold air pressure or density, respectively. The automatic mixture ratio control device may thus include the mechanism of Figure 1 minus lever 79 in combination with the structure represented in Figures 3 and 4. The rod 93, shown in part in Figures 3 and 2, is of course the same'as the rod 93 of Figure 1 and is actuated by the same structure as the rod 93 of Figure 1.

Figure 3 shows means for automatically regulating the fuel-air ratio as a function of the induction or manifold pressure, assuming the mixture control lever 78 to be in lean adjustment with rod 138 in the position shown in the drawing, thus permitting contact between the horizontal arm of lever 137 and the cam 146. A bellows 141, evacuated totally or in part and enclosed in a housing communicating with the engine induction pipe 62, operates rod 142 of a servo mechanism similar to those already described, whereby an increase in induction pressure raises rod 142 and causes lever 143 to be rotated counterclockwise until the increase load of the tension spring 144 re-establishes the balance of rod 142 in its neutral position. Lever 143 is secured to an externally splined sleeve 147 rotatably mounted on an engine-driven shaft 145. The warped cam 146 is slidably but nonrotatably mounted with respect to sleeve 147, so that the angular setting of the cam is dependent on the induction pressure. If the bellows 141 is not completely evacuated, it is responsive to changes of surrounding temperature, such as the induction or manifold temperature; and the angular adjustment of cam 146 is accordingly altered upon variations of said temperature. The axial setting of cam 146 is determined by speed responsive means such as a governor 148 driven from the engine through the shaft 145. This governor 148 controls rod 149 of a servo mechanism whereby an increase in engine speed displaces rod 149 to the left and thus causes the lever 150 to be rotated clockwise until the increased force of tension spring 151 restores the balance of rod 149 in its neutral position. Cam 146 therefore determines for each value of induction pressure and engine speed a corresponding minimum possible value of fuel-air ratio. In the preferred embodiment the form of the cam is such that in the cruising range of induction pressure and engine speed combinations such minimum corresponds to the best economy mixture, while for combinations of engine speeds and induction pressures corresponding to higher power output the minimum possible value of fuel-air ratio will be higher that that corresponding to best economy" mixture. Variation of fuel-air ratio as determined by cam 146 is obtained automatically if the mixture control lever 78 is adjusted for lean" mixture, owing to the The upper arm of lever 137 is connected with the 7 elongated slot 138 and spring 139, while further mixture enrichment may be obtained by rotating lever 78 counterclockwise.

It is clear from the foregoing that in the liquid fuel supply system described, the rate of engine fuel supply is controlled by means of the pilots lever 108. Clockwise rotation thereof causes clockwise rotation of the lever 127 and shifts the fuel control member 106 to the right so as to increase the flow of fuel, while the fuelair ratio is automatically controlled and caused to Vary as a function of various operating parameters such as temperature, altitude and speed. And it will be appreciated that whenever the pilots lever 108 is so set as to call for a rate of fuel which is out of proportion with the actual engine air flow, so that an excessively high fuel-air ratio would result, the power piston 116 will be caused to move so far to the right as to take up the lost motion within the elongated slot 121 and stop the clockwise rotation of lever 127 thereby limiting the rate of fuel flow to a proper value. The power piston 116 may even move further and turn the lever 127 counter-clockwise to decrease the fuel-air ratio. It is therefore clear that the lost-motion connection 121, adjusted by the servo piston 116, operates in effect as a variable stop for limiting the flow of fuel to maintain the desired fuel-air proportions. In particular, it will be understood by those skilled in the art that one of the inherent characteristics of the control device as disclosed above is that where the engine is operating at low speed, with the air compressor 61 developing only a low charging pressure and with a limited flow of air, if the pilots lever 108 is suddenly moved to wide open position, the fuel flow tends to increase suddenly and out of proportion with the low air flow, and the pilot valve 114115 becomes unbalanced and causes the power piston 116 to move so far to the right that the connecting element 121 becomes effective as a stop for the lever 127 and operates to maintain the fuel-air ratio within the desired limits. Whereupon, as the engine accelerates and the engine air flow increases, the stop 121 automatically recedes so as to permit the flow of liquid fuel gradually to attain the high value which may be necessary for full power operation. The rate of recession of the stop or limiting member 121 is automatically computed and scheduled so as to produce the proper rate of fuel fiow variation in preselected relation to engine speed, engine temperature, induction air temperature, or compressor discharge pressure. For example, it will be clear to any person skilled in this art that the centrifugal force applied by the fly weights 148 through the servomotor 149 moves the earn 146 at a rate proportional to the rate of variation of engine speed. The cam, in turn, controls the rate of motion of the limiting member 121 and therefore also the rate of change of fuel flow as a function of engine acceleration. Similar remarks apply also to the operation of the various components sensing the engine temperature, the intake air temperature and the pressure in the intake air system, It will therefore be appreciated that the control system described above, which is usually referred to in the art as a cam type speed density fuel control device, is particularly effective to compute and schedule the rate of fuel flow as well as the rate of change of said flow during transient engine operating conditions.

The foregoing embodiments of the invention have been described for purpose of illustration and not as a limitation of the scope of the invention. It is therefore to be especially understood that the invention is not limited to the specific embodiments shown, but may be used' in various other ways, in connection with other mechanisms and regulators, that various modifications may be made to suit different requirements, and that other changes, substitutions, additions and omissions may be made in the construction, arrangement and manner of operation of the parts without departing from the limits or scope of the invention as defined in the following claims.

Where the claims are directed to less than all of the ell) 8 elements of the system disclosed, they are intended to cover possible uses of the recited elements in installations which lack the non-recited elements.

I claim:

1. In a liquid fuel feed system for an engine having an air intake system, the combination with a fuel pump in said fuel feed system, of a control member movable in one direction to increase the flow of fuel supplied from the pump to the engine and movable in the opposite direction to decrease said flow of fuel to the engine, normaily operative control means subject to manual supervision for moving said control member to control the flow of fuel to the engine, abutment means rigidly connected to said control member to move therewith, a stop adjustable independently of said control member and including normally disengaged cooperating abutment means having a lost motion connection with the first said abutment means and adapted for engagement therewith to override said normally operative control means and limit the movement of said control member in the sense of increasing the flow of fuel to the engine, adjusting means for positioning said stop, and engine speed responsive means and means responsive to temperature variations in said air intake system for actuating said adjusting means.

2. In a liquid fuel supply system for an engine having an air inlet system, the combination with a-fuel control member movable in one direction to increase the flow of fuel to the engine and movable in the opposite direction to decrease the flow of fuel to the engine, of normally operative control means subject to manual supervision for moving said fuel control member to control the fiow of fuel to the engine, abutment means rigidly connected to said fuel control member to move therewith, a stop adjustable independently of said fuel control member and including normally disengaged cooperating abutment means having a lost motion connection with the first said abutment means and adapted for engagement therewith to render said normally operative control means ineffective and limit the movement of said fuel control member in the sense of increasing the flow of fuel, and engine speed responsive means and means responsive to temperature variations in said air intake system operatively connected with said stop for positioning the same.

3. In a liquid fuel supply system for an engine having an air intake system, a control mechanism comprising a fuel control element movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease the flow of fuel to the engine, normally operative control means including a manually operable member for adjusting said fuel control element to regulate the engine fuel flow, variable stop means cooperating with said control element and capable of over-riding said normally operative control means for limiting the adjustment of said fuel control element in the sense to increase the engine fuel flow, and engine operating conditions responsive means including engine speed responsive means and temperature responsive means for adjustably positioning said stop means so as to limit the maximum adjustment of said fuel control element to a predetermined safe value.

4. In a liquid fuel supply system for an engine having an air intake system, a control mechanism comprising a fuel control element movable in one direction to increase the fiow of fuel to the engine and in the opposite direction to decrease the flow of fuel to the engine, normally operative control means including a manually operable membet for adjusting said fuel control element to regulate the engine fuel flow, variable stop means cooperating with said control element and capable of over-riding said normally operative control means for limiting the adjustment of said fuel control element in the sense to increase the engine fuel flow, and engine operating conditions responsive means including engine temperature level responsive means for adjustably positioning said stop means so as to limit the maximum adjustment of said fuel control element to a predetermined safe value under the prevailing operating conditions.

5. In a liquid fuel supply system for an engine having an air intake system, a control mechanism comprising a fuel control element movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease the fiow of fuel to the engine, normally operative control means including a manually operable member for adjusting said fuel control element to regulate the engine fuel flow, variable stop means cooperating with said control element and normally disengaged but capable of over-riding said normally operative control means for limiting the adjustment of said fuel control element in the sense to increase the engine fuel flow, and engine operating conditions responsive means including engine operating temperature responsive means and air intake pressure responsive means for adjustaby positioning said stop means.

6. In a liquid fuel supply system for an engine having an air intake system with an air compressor therein, the combination with a liquid fuel control element movable in one direction to increase the flow of fuel to the engine and movable in the opposite direction to decrease the flow of fuel to the engine, of first control means subject to manual supervision for adjusting said fuel control element to regulate the engine fuel flow, normally disengaged stop means adapted to limit the movement of said fuel control element thereby over-riding the first control means and rendering the same ineffective, and compressor discharge pressure responsive means and means responsive to changes in engine operating temperature operatively connected to said stop means for positioning the same.

7. In a liquid fuel supply system for an engine having an air intake system, the combination with a liquid'fuel control element movable in one direction to increase the flow of fuel to the engine and movable in the opposite direction to decrease the flow of fuel to the engine, of first control means subject to manual supervision for adjusting said fuel control element to regulate the engine fuel flow, normally disengaged variable stop means adapted to engage said fuel control element to limit the movement thereof in the direction to increase the flow of fuel, a servomotor for adjustably positioning said stop means, and means for controlling the servomotor, including air intake temperature responsive means, engine operating temperature responsive means, and air intake pressure responsive means.

8. In a liquid fuel supply system for an engine, the combination with a fuel control element movable in one direction to increase the flow of fuel to the engine and movable in the opposite direction to decrease the flow of fuel to the engine, of a first control device subject to manual supervision for adjusting said fuel control element to regulate the engine fuel flow, abutment means rigidly connected to said fuel control element to move therewith, a stop adjustable independently of said first control device and including normally disengaged cooperating abutment means having a lost motion connection with the first said abutment means and adapted for engagement therewith to override said first control device and limit the movement of said fuel control element in the senseto increase the flow of fuel, and a second control device for variably positioning said stop, including a three dimensional cam, first adjusting means for axially positioning the cam, second adjusting means for angularly positioning said cam, a first sensor device responsive to a first engine operating condition for actuating one of said adjusting means, and a second sensor device responsive to a second engine operating condition for actuating the other adjusting means, whereby the engine fuel fiow is limited to a predetermined maximum safe value for each combination of said first and second engine operating conditions.

9. In a liquid fuel supply system for an engine having an air induction system, the combination with a fuel control element movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease said flow, of first control means subject to manual supervision for adjusting said fuel control element to regulate the engine fuel flow, abutment means rigidly connected to said fuel control element to move therewith, a variable stop adjustable independently of said first control means and including normally disengaged cooperating abutment means having a lost motion connection with the first said abutment means and adapted for engagement therewith to override said first control means and limit the movement of said fuel control element in the sense to increase the flow of fuel, and second control means for variably positioning said step, including a slidable and rotatable three dimensional cam, first adjusting means for axially positioning said cam, second adjusting means for angularly positioning said cam, engine speed responsive means for actuating one of said adjusting means, and temperature responsive means for sensing temperature changes in said air induction system to actuate the other adjusting means.

10. In a liquid fuel supply system for an engine having an air induction system, the combination with a fuel control element movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease said flow, of first control means for adjusting said fuel control element to regulate the engine fuel flow, abutment means rigidly connected to said fuel control element to move therewith, a variable stop adjustable independently of said first control means and including cooperating abutment means having a lost motion connection with the first said abutment means and adapted for engagement therewith to override said first control means and limit the movement of said fuel control element in the sense to increase the flow of fuel, and second control means for variably positioning said stop, including a slidable and rotatable three dimensional cam, first adjusting means for axially positioning said cam, second adjusting means for angularly positioning said cam, engine speed responsive means for actuating one of said adjusting means, and pressure responsive means for sensing pressure variations in said air induction system to actuate the other adjusting means.

11. In a liquid fuel supply system for an engine having an air induction system with an air compressor therein, the combination with a fuel control element movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease said flow, of first control means for adjusting said fuel control element to regulate the engine fuel flow, a variable stop adjustable independently of said first control means and having a lost motion connection with said fuel control element, said stop being adapted for engagement with said fuel control element to override the first control means and limit the movement of said fuel control element in the sense to increase the flow of fuel, and second control means for variably positioning said stop, including a cam follower operatively connected with said stop, a three dimensional cam for actuating the cam follower, said cam having two different ways of motion relative to the cam follower, engine speed responsive means for moving the cam in one of said ways, and means respon sive to the pressure in said air induction system on the discharge side of said compressor for moving the cam in the other way.

12. In a liquid fuel supply system for an engine having an air intake system, the combination with a fuel control element movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease said flow of fuel, of first control means operatively connected with said fuel control element for variably positioning the same to control the engine fuel flow, a variable stop having a lost motion connection with said fuel control element and adapted to engage the same for overriding the first control means and limiting the movement of said fuel control element in the direction to increase the flow of fuel to the engine; and a control mechanism for positioning said stop, said control mechanism including means for selecting an engine fuel-air ratio varying as a predetermined function of at least one engine operating parameter, and means for comparing the actual fuel-air ratio with the selected fuel-air ratio, the arrangement being such that when the actual ratio tends to exceed the selected ratio the said control mechanism becomes operable to move the stop and so limit the maximum flow of fuel as to prevent the fuel-air ratio from exceeding the preselected value thereof under the prevailing operating conditions.

13. In a liquid fuel supply system for an engine having an air intake system, the combination with a liquid fuel control element movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease the same, a first mechanism including a manually operable engine control member operatively connected to position said fuel control element, and adjustable stop means capable of overriding said first mechanism for variably limiting the maximum fuel flow setting of said fuel control element, of a computer mechanism including a first sensor device and selector means for selecting a fuel-air ratio changing as a predetermined function of an engine operating condition, additional sensor means for comparing the actual fuelair ratio with the selected fuel-air ratio, and motor means actuated in response to increase of the actual fuel-air ratio above the selected fuel-air ratio for moving the stop to lower the maximum limit of liquid fuel flow obtainable by operation of said first mechanism.

14. In a liquid fuel supply and control system for an engine having an air intake system, the combination with a liquid fuel control element movable in one direction to increase the fiow of fuel to the engine and in the opposite direction to decrease the same, a first mechanism operatively connected to position said fuel control element, and adjustable stop means capable of overriding said first mechanism for variably limiting the maximum fuel flow setting of said fuel control element, of a computer mechanism including first sensor means connected with said air intake system for sensing engine air flow, second sensor means operatively associated with said liquid fuel system for sensing engine fuel flow, a selector device including means responsive to an engine operating parameter for selecting a variable ratio between fuel flow and air flow, which ratio changes as a preselected function of said parameter, and means for comparing the actual fuel-air ratio with the selected ratio and resetting the stop means when the actual ratio tends to exceed the selected value, so as to prevent overfuelling irrespective of the operation of said first mechanism.

15. In a liquid fuel supply and control system for an engine having an air inlet system, the combination with liquid fuel control means movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease the same, of resilient means for biasing said fuel control means in the direction to increase the flow of fuel, a first control mechanism including a manually operable member operatively connected with said fuel control means for positioning the same in opposition to said resilient means to control the engine power output, an adjustable stop cooperating with said fuel control means and movable relative thereto, which stop forms a restraint on the degree of movement of the fuel control means in the sense to increase the flow of fuel, and a second control mechanism including engine speed responsive means and additional condition responsive means connected with said air inlet system for adjusting said stop.

16. In an engine liquid fuel supply and power control system, the combination with a liquid fuel control ele-.

tent movable in one direction to increase the flow of fuel to the engine and in the opposite direc'tion'to decrease the same, resilient means for biasing said fuel control element in the direction to increase the flow of fuel, a first control mechanism subject to manual supervision for engaging said fuel control element and acting against said resilient means to position said fuel control element, a second control mechanism operable independently of the first control mechanism for engaging said fuel control element and acting against said resilient means to position said fuel control element, whereby each of said control mechanisms is adapted to override the other and take over control of the fuel control element, said second control mechanism including engine speed responsive means and additional means responsive to a temperature affecting engine operation to define a maximum permissible fiow of fuel which varies automatically as a preselected funcion of said speed and temperature.

17. In an engine liquid fuel supply and control system, the combination with a fuel control member movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease the same, of abutment means connected to said fuel control member, a first control mechanism including co-operating abutment means for engaging the first said abutment means to move the fuel control member in the direction to decrease the flow of fuel, resilient means connected with said first mechanism and with said fuel control member for yieldingly holding said first and second mentioned abutment means in engagement with one another, an additional control mechanism operable independently of said first control mechanism and including means movable with respect to said fuel control member for engaging the same to overcome the force of said resilient means, disengage the fuel control member from the first control mechanism and move the fuel control member in the direction to decrease the flow of fuel, and engine speed responsive means and means responsive to a temperature affecting engine operation in said additional control mechanism for causing the same to limit the maximum fuel flow obtainable by means of said first control mechanism automatically as a preselected function of said speed and temperature, thereby rendering the first control mechanism ineffective whenever the same calls for excessive flow of fuel under existing operating conditions.

18. In a fuel supply and control system for an engine having an air intake system, the combination with a fuel control member movable in one direction to increase the flow of fuel to the engine and in the opposite direction to decrease the same, of a first control mechanism for engaging said fuel control member to move the same in the direction to decrease the flow of fuel, resilient means connected with both the first control mechanism and the fuel control member for yieldingly holding the same in engagement with one another, a second control mechanism operable independently of the first control mechanism for engaging said fuel control member to overcome the force of said resilient means, disengage from the first control mechanism the fuel control member and move the same in the direction to decrease the flow of fuel, and means rcsponsive to a temperature affecting engine operation, means responsive to pressure in the air intake system and engine speed responsive means in the second control mechanism for causing the same automatically to take over operation of the fuel control member whenever necessary in order to limit the maximum fuel flow to a preselected function of said temperature, pressure and speed, thereby rendering the first control mechanism ineffective when ever it so operates as to call for a rate of fuel flow which is excessive under existing operating conditions.

19. In a fuel supply and control system for an engine having an air intake system, the combination with a fuel control member movable in one direction to increase the fiowof fuel to the engine and in the opposite direction to decrease the same, of a first control mechanism for moving the fuel control member in the direction to decrease 13 the flow of fuel, resilient means connected with said first mechanism and With said fuel control member for yieldingly holding the same in engagement with one another so as to move together, a second control mechanism operable independently of said first control mechanism and having a lost-motion connection With the fuel control member but capable of overcoming the force of said resilient means, disconnecting from the first control mechanism the fuel control member and moving the same in the direction to decrease the flow of fuel, and means responsive to pressure variations in said air intake system and means responsive to a temperature affecting engine operation in said additional control mechanism for causing the same to become operative so as to limit the maximum obtainable fuel flow automatically as a preselected function of said pressure and temperature, thereby rendering the first control mechanism ineffective whenever the operation thereof calls for excessive flow of fuel under existing operating conditions.

20. In a fuel control system for an engine, a fuel metering control member movable to different positions to vary the rate of fuel flow in relation to travel of said control member, first adjustable means operatively connected to said control member for effecting movement thereof, stop means movable through different flow regulating positions effective to limit the travel of said control member to a metering rate conforming to a predetermined engine acceleration schedule, and means responsive to a plurality of engine operating parameters for variably positioning said control member.

21. In a liquid fuel control system for an engine, the combination with a fuel control member movable to different positions to vary the rate of fuel fiow in relation to travel of said control member, of adjustable engine control means operatively connected to said control member for effecting movement thereof, stop means movable through different flow regulating positions effective to limit the travel of said control member to a metering nate conforming to a predetermined engine acceleration schedule, and means for controlling the rate of movement of said limiting means as a function of engine speed plus an engine operating temperature.

22. In a liquid fuel control system for an engine having an air induction system, the combination with a fuel control member movable to different positions to vary the rate of fuel flow in relation to travel of said control member, of adjustable engine control means operatively connected with said member for effecting movement thereof, stop means movable through different fiow regulating positions effective to limit the travel of said control member in accordance to a preselected engine acceleration schedule, three-dimensional cam means, and means responsive to the speed of the engine and a condition of the air in said induction system for moving said three-dimensional cam'means to position the stop means.

23. In an engine fuel supply and control system, the combination with a fuel pump, of movable fuel control means for varying the rate of fuel flow supplied from the pump to the engine, a first mechanism for moving said fuel control means to accelerate and decelerate the engine and regulate the engine speed, limiting means for overriding said first mechanism and controlling said fuel control means to regulate the rate of fuel fiow, and means responsive to changes of engine speed for adjusting said limiting means, whereby upon sudden motion of said first mechanism in the direction to accelerate the engine said limiting means take over control of said fuel control means to limit the rate of increase of fuel flow as a predetermined function of engine speed.

24. In an engine fuel supply and control system, the combination with movable fuel control means for varying the rate of engine fuel flow, of a first mechanism for moving said fuel control means to accelerate and decelerate the engine, limiting means for overriding said first mechanism and actuating said fuel control means to regulate the rate of fuel flow, and means responsive to changes of engine operating temperature for adjusting said limiting means, whereby upon motion of said first mechanism to accelerate the engine said limiting means may take over control of said fuel control means so as to limit the rate of increase of fuel flow as a preselected schedule of said temperature.

25. In a fuel supply and control system for an engine having an air inlet system with a compressor therein, the combination with movable fuel control means for varying the rate of engine fuel flow, of a first mechanism for moving said fuel control means to accelerate and decelerate the engine, limiting means for overriding said first mechanism and actuating said fuel control means to regulate the rate of fuel flow, and means responsive to changes of air pressure on the discharge side of said compressor for adjusting said limiting means, whereby upon motion of said first mechanism to accelerate the engine s'aid limiting means may take over control of said fuel control means so as to limit the maximum rate of increase of fuel fiow according to a preselected function of the compressor discharge pressure.

26. A fuel supply and control system as claimed in claim 23, further including means responsive to the temperature of the air in the engine air inlet system operatively connected with the engine speed responsive means for modifying the effect thereof upon the limiting means.

27. A fuel supply and control system as claimed in claim 23, further including means responsive to engine induction air pressure for varying the effect of the engine speed responsive means upon the limiting means.

28. In an engine fuel supply and control system, the combination with fuel control means movable to increase or decrease the rate of engine fuel flow, of a first mechanism for adjusting said fuel control means to accelerate or decelerate the engine, limiting means adapted to control said fuel control meansindependently of said first mechanism for variably limiting the maximum rate of fuel flow, means responsive to changes in engine speed, additional sensor means responsive to variations in another engine operating parameter, and an operative connection between said speed responsive means, additional sensor means and limiting means for positioning the limiting means to maintain the rate of engine fuel fiow within a predetermined maximum limit for each set of engine operating conditions irrespective of the operation of said first mechanism.

29. In engine control apparatus for an engine having a throttle for controlling the flow of fuel to said engine, a throttle positioning member adapted to be connected to an engine throttle, a manually controlled member, a lost motion mechanical connection between said manually controlled member and said throttle positioning member, a motor also connected to said throttle positioning member for positioning said member Within the range of lost motion provided by said connection, and means for re motely controlling said motor.

30. In engine control apparatus for an engine having a throttle for controlling the flow of fuel to said engine, a throttle positioning member adapted to be connected to an engine throttle, a manually controlled member, a lost motion mechanical connection between said manually controlled member and said throttle positioning member, a motor also connected to said throttle positioning member for positioning said member within the range of lost motion provided by said connection, and means adapted to respond to an engine temperature for controlling said motor.

31. In engine control apparatus for an engine having a throttle for controlling the fiow of fuel to said engine, a throttle positioning member adapted to be connected to an engine throttle, a manually controlled member, a lost motion mechanical connection between said manually controlled member and said throttle positioning member, a motor also connected to said throttle positioning member for positioning said member Within the range of lost motion provided by said connection, means adapted to respond to a temperature condition affecting engine operation for controlling said motor, and means positioned by said manually controlled member for varying the control point of said last named means.

32. In engine control apparatus for an engine having a throttle for controlling the flow of fuel to said engine, a throttle positioning member adapted to be connected to an engine throttle, a manually controlled member, a lost motion mechanical connection between said manually controlled member and said throttle positioning member, a motor also connected to said throttle positioning member for positioning said member within the range of lost motion provided by said connection, means adapted to respond to a condition affecting engine operation for controlling said motor, spring means associated in biasing relation with said condition responsive means, and connecting means between said manually controlled member and said spring means for varying the biasing action of said spring means to vary the control point of said condition responsive means.

33. In engine control apparatus for an engine having fuel control means for controlling the fiow of liquid fuel to said engine, positioning means for positioning said fuel control means, a first mechanism subject to manual supervision, a lost motion mechanical connection between said first mechanism and said positioning means, a second mechanism, including motor means also connected to said control means for positioning the same within the range of lost motion provided by said connection and for regulating the speed of motion of said control means, and means adapted to respond to changes in a temperature of the engine for controlling said motor means.

34. In engine control apparatus for an engine having liquid fuel control means, positioning means for said fuel control means, a first mechanism subject to manual supervision, a lost motion mechanical connection between said first mechanism and said positioning means, a second mechanism including motor means also connected to said positioning means for positioning the same within the range of lost motion provided by said connection and for regulating the rate of motion of said positioning means, and a plurality of means each adapted to respond to changes in a condition affecting engine operation for controlling said motor means.

35. In engine control apparatus for an engine having liquid fuel control means, positioning means for said fuel control means, a first mechanism subject to manual supervision, a lost motion mechanical connection between said first mechanism and said positioning means, a second mechanism including a three dimensional cam also connected to said positioning means for positioning the same within range of lost motion provided by said connection, a plurality of sensor means each adapted to respond to variations in a condition affecting engine operation, and connecting means inciuding motor means for positioning the three dimensional cam from said sensor means.

36. In engine control apparatus for an engine having a throttle for controlling the flow of fuel to said engine, a throttle positioning member adapted to be connected to an engine throttle, a manually controlled member, connecting means between said manually controlled member and said throttle positioning member effective to rigidly connect said members at throttle closed position but providing for a range of independent movement of said throttle positioning member towards open position when said manually controlled member is moved in throttle opening direction, and means for independently moving said throttle positioning member within range.

37. In engine control apparatus for an engine having a throttle for controlling the fiow of fuel to said engine, a throttle positioning member adapted to be connected to an engine throttle, a manually controlled member, connecting means between said manually controlled member and said throttle positioning member effective to rigidly connect said members at throttle closed position but providing for a range of independent movement of said throttle positioning member towards open position when said manually controlled member is moved in throttle opening direction, a motor for moving said throttle positioning member within said range, and means adapted to respond to a condition affecting engine operation for controlling said motor.

38. In an engine fuel supply and control system, the combination with a fuel pump and conduit means connected with the pump for delivering fuel to the engine, of fuel regulating means movable in one direction to increase the rate of fuel How to the engine and in the opposite direction to decrease the same, a first control mechanism normally operable to position said fuel regulating means to control engine operation and movable in either direction to accelerate or decelerate the engine, maximum limiting means for overriding the action of said first control mechanism and taking over operation of said fuel regulating means during acceleration to prevent excessive rates of fuel flow, and sensor devices responsive to a temperature condition of the engine and to engine speed for actuating said limiting means to reduce the rate of fuel flow to the engine to a safe operating level while maintaining optimum acceleration rates.

39. In a fuel supply and control system for an engine having an air intake system with a compressor therein, the combination with a fuel pump and conduit means connected with the pump for delivering fuel to the engine, of fuel regulating means movable to increase or decrease the rate of fuel flow to the engine, a first control mechanism operable to position said fuel regulating means to control engine operation, maximum limiting means becoming operational under predetermined conditions for over-riding the action of said first control mechanism and taking over control of said fuel regulating means to limit the maximum rate of fuel flow, first and second sensor devices responsive respectively to temperature in said air intake system and to engine speed for adjusting said limiting means, and additional regulating means including a sensor device responsive to the pressure on the discharge side of said compressor for varying the rate of fuel fiow substantially in direct proportion to said pressure.

40. In a fuel supply and control system for an engine having an air intake system, the combination with a fuel pump and conduit means connected with the pump for delivering fuel to the engine, of fuel regulating means movable in one direction to increase the rate of engine fuel flow and in the opposite direction to decrease the same, a first control mechanism for positioning said fuel regulat ing means to control engine operation, maximum limiting means for overriding the action of said first control mechanism and taking over control of said fuel regulating means to limit the maximum rate of fuel flow, a slidable and rotatable three-dimensional cam, cam follower means for positioning said maximum limiting means from said cam, first adjusting means for rotating said cam, second adjusting means for moving said cam axially, a sensor device connected with said air intake system and responsive to a condition of the air therein for actuating one of said adjusting means, and an engine speed responsive device for actuating the other adjusting means.

41. In a fuel supply and control system for an engine having an air intake system, the combination with movable fuel control means for regulating the rate of engine fuel flow, of a first mechanism for adjusting said fuel control means to control engine speed or power output, maximum limiting means for overriding said first mechanism and actuating said fuel control means to set an upper limit to the rate of fuel flow obtainable by operation of said first mechanism, means responsive to changes of engine operating temperature for adjusting said maximum limiting means to vary said upper limit as a function of said temperature, and additional means responsive to changes of air'pressure in said air intake system for effecting an flow obtainable by operation of said first mechanism,

means responsive to engine operating temperature and means responsive to engine speed for adjusting said maximum limiting means to vary said upper limit as a function of said temperature and speed, and additional means responsive to changes of air pressure in said air intake system for efifecting an increase or decrease of said upper limit upon increase or decrease of said air pressure, respectively.

43. A fuel control system for providing fuel flow Within a limited range to an engine having an air intake passage with a compressor therein, including fuel control means movable to regulate the rate of fuel flow, a first mechanism including a power setting lever for positioning said fuel control means to control engine operation, maximum limiting means for overriding said first mechanism and operating said fuel control means to limit the maximum rate of engine fuel flow, a pressure responsive device for measuring the pressure of the air in said passage on the discharge side of the compressor, and means for positioning said maximum limiting means from the pressure responsive device to vary the upper limit imposed on the rate of fuel flow in response to said pressure.

44. In a fuel-air ratio and temperature control system for an engine having an air intake passage with a compressor therein and a fuel supply system provided with fuel control means for regulating the rate of fuel flow to the engine, a first mechanism for varying the setting of said fuel control means to control engine operation, maximum limiting means for overriding said first mechanism and actuating said fuel control means in the sense to limit the maximum rate of fuel flow obtainable by operation of said first mechanism, means responsive to compressor air pressure co-operating With said maximum limiting means to impose an upper limit to the ratio of fuel to combustion air, and additional means responsive to engine temperature operatively connected to said maximum limiting means for varying the operating adjustment thereof in response to said temperature.

45. In an engine, a source of fuel under pressure, fuel control means for regulating the flow of fuel to the engine, a power setting lever, an operative connection for actuating said fuel control means as a function of the setting of said lever, and maximum limiting means operatively connected to said fuel control means for limiting the fuel flow obtainable by operation of said power setting lever as a function of an engine pressure signal, a function of engine speed, and a function of an engine temperature.

46. In an acceleration and temperature control system for an engine having an air intake passage with a compressor therein and a fuel supply system provided with .fuel control means for regulating the rate of fuel flow to the engine, a first device for varying the adjustment of said fuel control means to control engine operation, maximum limiting means for overriding said first device and actuating said fuel control means in the sense to limit the maximum rate of fuel obtainable by operation of said first device, a servomechanism responsive to changes of compressor air pressure and co-operating with said maximum limiting means to impose an upper limit to the ratio of fuel flow to combustion air flow, and additional servomechanisms actuated in response to changes in engine speed and variations in an engine temperature for altering the operating adjustment of said maximum limiting means as a function of saidspeed and temperature.

47. In a fuel supply and control system for an engine having an air intake system, the combination with a fuel pump, of movable fuel control means for varying the rate of fuel flow supplied from the pump to the engine, a first mechanism for moving said fuel control means to accelerate and decelerate the engine and regulate the engine speed, limiting means for overriding said first mechanism and controlling said fuel control means to regulate the rate of fuel flow, means responsive to changes of engine speed for adjusting said limiting means, and additional means responsive to pressure and temperature in said air intake system for modifying the effect of said means responsive to speed changes, whereby upon sudden motion of said first mechanism in the direction to accelerate the engine said limiting means take over control of said fuel control means to limit the rate of increase of fuel flow as a predetermined function of engine speed and intake air conditions.

48. In a fuel supply and control system for an engine having an air intake system, the combination with movable fuel control means for varying the rate of engine fuel flow, of a first mechanism for moving said fuel control means to accelerate and decelerate the engine, limiting means for overriding said first mechanism and actuating said fuel control means to regulate the rate of fuel fiow, means responsive to changes of engine operating temperature resulting from combustion for adjusting said limiting means, and means responsive to temperature in said air intake system for modifying the effect of the first-mentioned temperature responsive means, whereby upon motion of said first mechanism to accelerate the engine said limiting means may take over control of said fuel control means so as to limit the rate of increase of fuel flow as a preselected schedule of said temperatures.

References Cited in the file of this patent UNITED STATES PATENTS 2,024,202 Berger Dec. 17, 1935 2,088,954 Gregg Aug. 3, 1937 2,136,959 Winfield Nov. 15, 1938 2,189,475 Saur Feb. 6, 1940 2,193,927 Jivkovitch Mar. 19, 1940 2,205,354 Gregg et a1 June 18, 1940 2,217,364 Halford et al. Oct. 8, 1940 2,244,669 Becker June 10, 1941 2,245,562 Becker June 17, 1941 2,341,257 Wunsch Feb. 8, 1944 2,382,707 Gosslau et al Aug. 14, 1945 FOREIGN PATENTS 458,350 Great Britain Dec. 17, 1936 

